非基岩场地核设施工程地基处理及对结构地震响应的影响

Foundation Treatment of Nuclear Facility Engineering on Non-rock Site and Its Impact on Structural Seismic Response

通过调研目前美国核安全结构地震分析相关的规范,探讨了非基岩场址地震动的合理输入位置和输入地震动的确定方法,并利用EERA程序和ACS SASSI软件分析了构筑物基础底部与基岩之间的土层厚度对上部核设施结构地震响应的影响.结果表明,土层厚度较薄时,结构的高频地震响应可能显著大于基岩地基上的结构地震响应,只有土层足够厚时,土层才对地震波高频分量有明显的过滤作用.针对以素混凝土置换地基土的处理方案进一步开展了结构地震响应分析,地基土置换处理的地基上的结构地震响应与基岩地基上的结构地震响应的对比,展示二者具有较为一致的结构地震响应结果,表明素混凝土换填的地基处理方案的有效性,并提出了换填地基与结构组合的计算分析模型.

The American standards about seismic analysis of safety-related nuclear structure were investigated,and the seismic input interface location of for non-rock site and the methods of determining input seismic motion were discussed,and then the effect of the soil layer thickness between structure foundation and base rock on seismic response of nuclear structure was analyzed by the professor software EERA and ACS SASSI.The results show that,at the relative high frequency components of the structural seismic response on the soil site are higher than those on rock site in the case of shallow overlay soil,and only in the case of sufficiently deep overlay soil,the reduction of relative high frequency components of the structural seismic response exists.Furthermore,the foundation treatment scheme of replacing soil with plain concrete was analyzed,and the comparison of structural seismic responses for the cases of the foundation treatment scheme and the hard rock foundation shows a reasonable good agreement,and also a numerical model of structure with the foundation of replacing soil with plain concrete was proposed.